For certain applications it is essential to apply service aware QoS-control to a large portion of the User Equipments, UEs, connected to a mobile communication network. An example of this is e.g. to in case of congestion be able to down prioritize IP-packets belonging to background type services in order to reduce the impact on services that are more sensitive from an end user point of view.
The procedures defined by 3rd Generation Partnership Project, 3GPP, to support dedicated bearers in 3rd Generation communication networks, 3G, and Evolved Packet Core, EPC/Long Term Evolution, LTE, based communication networks require support of specific functionality in the UE. At present there are in principle no 3G UEs that supports this functionality. For LTE the dedicated bearer has been defined from the start and it can probably be assumed that most UEs will have this kind of support, however, there might be scenarios where service differentiation is preferable without the need to trigger a new bearer setup. One has to keep in mind that each bearer setup requires signalling overhead between the network and the UE. There will, for a long time, be a relatively large portion of the UEs that are lacking support for dedicated bearers which will significantly limit the possibility for an efficient result of down prioritizing background type traffic in congestion situations.
One solution to convey the information regarding the type of service, i.e. application, traffic pattern, device type, subscription type or combination of any of those, is to use some specific General Packet Radio Service Tunnelling Protocol User Plane, GTP-U, header fields to transmit the service type information from e.g. the Gateway GPRS Support Node, GGSN, or Serving Gateway, SGW, or Packet Data Network Gateway, PDN-GW, down to the RAN. In the case of Global System for Mobile communication EDGE Radio Access Network, GERAN, the information would need to be also transmitted from the Serving GPRS Support Node, SGSN, to the RAN using Base Station System GPRS Protocol, BSSGP, header fields (i.e. first using GTP-U from the GGSN to the SGSN and the BSSGP from the SGSN to the BSC/PCU). The main reason for this is that the SGSN may perform ciphering on the IP packets before forwarding the IP packet to the RAN. Therefore the IP packet may not be readable in the RAN and other means like the GTP-U header field marking are needed for this case.
The usage of a GTP-U header field has some limitations as the GTP-U protocol is initiated in the downlink first from the GGSN or SGW/PDN-GW. This effectively prohibits the placement of the DPI functionality above these nodes. However, mobile operators do currently have DPI functionality implemented above these nodes, hence the mobile operators are severely restricted in where to place or implement DPI functionality when using the GTP-U header field. It shall be pointed out that there are other packet networks than those defined by 3GPP and the same objects and problem may apply to them with regards to how to handle e.g. QoS, congestion situations. This disclosure is not limited to 3GPP networks but applicable to any packet networks.